Eating cruciferous vegetables such as sprouts, broccoli and cauliflower at least once a week can cut the risk of developing a variety of cancers.

Those who ate them at least weekly cut the risk of mouth cancer and breast cancer by almost a fifth and oesophageal cancer by more than a quarter, a study has found.

The research linked poor diet with the fatal disease with around a third of all cases of oral cancer is thought to be linked to an unhealthy diet.

Previous studies have found that a particular nutrient in cruciferous vegetables, which also include cabbage, watercress and radish, can kill cancer cells and gives potential for the production of new drugs.

The results, published in the Annals of Oncology, found that the risk of kidney cancer was cut by almost a third and colorectal cancer by almost a fifth.

Chief Executive of the British Dental Health Foundation, Dr. Nigel Carter wanted to highlight the link between poor diet and mouth cancer.

He said: “Around a third of all cases of oral cancer are thought to be linked to an unhealthy diet.

“The number of people being diagnosed with mouth, throat and food pipe cancer is continually rising.

“The Foundation recommends that people ensure they eat a healthy, balanced diet, with plenty of fruit and vegetables.”

Researchers believe that unhealthy habits and diet may be reasons behind the rise in oral cancer.

Dr. Nigel Carter said: “Researchers believe this is due to excessive smoking, drinking and an unhealthy diet among the young, while new research shows a dramatic rise in oral cancer as a result of the human papilloma virus and oral sex.

“We must not forget tobacco is still the most likely cause of mouth cancer, linked to around three-quarters of all cases of a disease which kills one person every five hours in the UK.

“With new cases occurring all the time, too many people still remain unaware of the risk smoking poses. Encouraging people to quit smoking and pursue a healthy lifestyle would reduce the risk of developing oral cancer.”

Oral cancer is a group of cancers including cancer of the lip, tongue, mouth, oropharynx, piriform sinus, hypopharynx and other and ill-defined sites of the lip, oral cavity and pharynx.